Well, you could have knocked us down with a feather boa. Of Brian Eno's first four solo albums, it turns out that his debut - Here Come The Warm Jets - is the only one to have charted: Number 26 for the blink of a glittery eye in March 1974. Just how differently Eno's career trajectory might have played out had he achieved mainstream success after leaving Roxy Music is open to conjecture. Professing little interest at the time in the business of idolatry, and already waving from way out left field, there can be little doubt that he would nevertheless have made a magnificent if momentary '70s pop star: just the kind of preening, androgynous, glam-dram, parent-baiting, proudly non-musical provocateur that us proles craved to see us through those long, dark, power-cut nights.

Pleasingly for audiophiles and discophiles alike, the first four Eno solo albums have now been afforded the half-speed-mastered-double-45rpm-LP-with-gatefold treatment. Between them, they trace Eno's piecemeal transition from yelping goad to zen ambassador of ambience, and make for a uniformly rewarding listen.

From the top, 1974's Warm Jets would still have been a keeper had it just been a broad-stroke lipstick slash from the very fag-end of glam, but Eno's well-entrenched art perspective lends form, substance and intrigue to some ostensibly random assemblages - an enduring cachet from chaos. If the chugging Needles In The Camel's Eye is clearly descended from The Velvet Underground's bloodline, the oppressive, cortège-paced Driving Me Backwards sounds as though it's coalescing, with considerable difficulty, from an epoxy swamp. Blank Frank is Bo Diddley with shingles, The Paw Paw Negro Blowtorch is joyously defaced with Eno's then-habitual VCS3 synth scrawls, and Baby's On Fire - its over-enunciated vocal sung through a mouth as wide as Kermit's letterbox - features an extended guitar solo of visionary oddness, with a note choice partly informed by voluntarily scuttling up blind alleys.

This embrace of happenstance was, of course, a central pillar of Eno's methodology: an approach legitimised by the infamous Oblique Strategies cards he devised with artist Peter Schmidt, and which came into play on 1974's Taking Tiger Mountain (By Strategy). Less spiky than its predecessor, the album breezes in with the languid, paw-licking, half-time groove of Burning Airlines Give You So Much More, then out-charms Kevin Ayers with the playful Back In Judy's Jungle. Third Uncle, meanwhile, is often touted as a precursor to punk, but that fidgeting bassline and those clattering tuned toms are closer to Bow Wow Wow. And, keeping the avant quotient topped up, The Portsmouth Sinfonia smear a bleary, out of focus grimace across the face of Put A Straw Under Baby.

However abstruse Eno's lyric preoccupations become, this is still pop music, just about: but Tiger Mountain's tranquil title track gazes longingly towards the still-life tendencies which flowered on 1975's Another Green World. Here, the emphasis is on evocative, painterly and minimalist instrumentals, many performed by Eno alone (In Dark Trees, Sombre Reptiles, and The Big Ship, which pilots a rudimentary drum machine through thick fog). That deathless title track - yes, the Arena theme - achieves a degree of poignancy out of all proportion to its five-note simplicity: and the swaying, Roxy-esque I'll Come Running reveals that Eno wasn't yet prepared to suppress his pop instincts altogether.

Speaking of which, 1977's Before And After Science strikes the most perfect balance between dissolute pop confectionery (King's Lead Hat, a brash love letter to the Talking Heads, and the perky Backwater - the best single Sailor never wrote) and the pellucid ambient ripples which constitute the album's second side. Julie With... and By This River in particular are still discernible as songs, but weigh as little as falling blossom.